package Demo1;

public class Computer{
    public void powerOn(){
        System.out.println("开机！");
    }

    public void powerOff(){
        System.out.println("关机！");
    }

    public void usbService(USB usb){
        usb.openDevice();
        if (usb instanceof Mouse){
            Mouse mouse = (Mouse) usb;
            mouse.click();
        }else if(usb instanceof Keyboard){
            Keyboard keyboard = (Keyboard)usb;
            keyboard.input();
        }
        usb.closeDevice();
    }
}
